In looms which utilize weft yarn that is furnished from an outside source and is not carried to and fro through the shed by the shuttle or carrier itself, it is common practice to insert each pick of weft by two reciprocating elements. In this form of shuttleless loom, the element which introduces the weft into the wrap shed is known as the inserting carrier and that which receives or has transferred to it the introduced weft to be drawn through the remainder of the shed is known as the weft receiving or extending carrier.
In the weaving of particular types of fabric, it is desirable to mix the weft yarns by drawing them from separate sources of supply so as to distribute variations therein and give the fabric a uniform overall appearance. By mixing weft yarns from different sources of supply patterning effects can be had by utilizing different types of weft yarn as well as weft yarns of a different color to form stripes, for example, and is accomplished by selecting one color or type of yarn for a predetermined number of picks and subsequently selecting a second and then a third and so on.
When weaving with a plurality of weft yarns in pick and pick type shuttleless looms to which the present invention is applicable, the various yarns extend from their source through known forms of guides and tensioning devices to and through the particular weft positioning element individual thereto. These positioning elements are effective in selectively moving their weft yarns between their inactive or storage position and that position whereat they will be taken by the inserting carrier and introduced into the warp shed. The positioning elements are usually provided with eyelets on their free ends through which a weft yarn extends and are engaged in relatively close proximity, one with the other, so that they have a substantially common active or selected position for presenting a weft yarn to the inserting carrier.
The required close positioning of the plurality of weft yarns in the area where they extend from their respective positioners to the edge of the fabric, has presented a very serious problem of certain types of weft yarns knitting or clinging together. Such a problem will oftentimes result in failure of the carrier to pick up and introduce a selected weft yarn or else it may even pick up and introduce more than one weft yarn. The latter condition is made possible when one yarn is being moved towards its selected position and becomes entangled with the previously selected yarn that is being simultaneously moved to its inactive position. The condition of failure to introduce a weft yarn can occur when a particular yarn to be selected has knit with or become entangled with an adjacent inactive yarn. In this event the selected yarn's positioner will move to the selected position but the entangled portion of the yarn will cling to the non-selected one and will not be lowered to its carrier pick-up position. Additionally the failure to introduce a weft yarn can also be caused by a selected weft yarn knitting with or clinging to an immediately adjacent inactive weft yarn in the area intermediate the thread cutter and the fabric edge. Such a condition will cause the non-selected weft to enter the weft cutter with the selected weft as the latter is guided into said cutter after being received into the guide slot formed in the back wall of the inserting carrier as the latter is caused to move toward the shed. The cutter will sever both the selected and non-selected wefts which will permit the selected weft to be introduced into the shed in a normal manner; however, when the severed inactive weft is again selected it will fail to be taken by the inserting carrier causing a cessation of loom operation. The types of weft yarn which are the most troublesome are those of low count having a fuzzy texture such as natural fibers or blends thereof as well as novelty yarns that vary in size and texture. The weft yarns are maintained under a predetermined amount of tension and any loss of tension which would create slack in the weft contributes highly to the possibility of adjacent weft yarns becoming entangled. A loss of tension in high twist yarn is especially troublesome for a slight amount of slack in such yarns will cause then to twist upon themselves to the extent of entanglement with adjacent yarns.
The weft yarn control device comprising the invention has eliminated the problems described above by providing a weft separator which is operatively associated with the weft positioners and is effective in assuring a positive separation between the weft yarns in their inactive positions and the selected yarn in its active position.